The team say the pill could improve current methods like faecal DNA and metabolites analysis. This approach provides little data of the environment upstream of the distal colon, where bacterial species can vary significantly.
"We are learning quite a lot about the role of gut microbiome in health and disease. However, we know very little about its biogeography," says Sameer Sonkusale, study team member and professor of electrical and computer engineering at Tufts University's School of Engineering.
"The pill will improve our understanding of the role of spatial distribution in the microbiome profile to advance novel treatments and therapies for a number of diseases and conditions."
Abnormal conditions unseen
The majority of microbiome studies use faecal DNA and metabolite analysis to gain an understanding of the gut microbiome state.
Because the gut environment changes as the gut content moves down the gastrointestinal (GI) tract, faecal analyses cannot identify abnormal conditions upstream of the distal colon.
Whereas complex bacterial populations analysis benefits from new DNA sequencing techniques, the research team say methods to precisely and non-invasively sample different organs has not improved.
“For example, samples important for understanding the interaction between enteric pathogens and the host remain out of reach, unless invasive sampling techniques are used,” they say.
“To gain new insights into the many beneficial functions of the gut microbiota, it is essential to sample in vivo different locations in the gut, particularly organs located upstream of the colon.”
The pill profile
The pill is described as a non-invasive technology to sample the intestinal lumen, specifically targeted to study the gut microbiome.
It is designed to be an ingestible, biocompatible, 3D-printed micro-engineered pill with integrated osmotic sampler that requires no battery for its operation.
Stereo-lithography (SLA) based 3D printing was used to create the miniaturised ingestible device with microfluidic functions for spatial sampling of the gut lumen.
The pill is also covered with a pH sensitive enteric coating to delay sampling until the pill has entered the small intestine, where the coating dissolves in the higher pH environment.
In addition, a magnetic holding mechanism enables the pill to sample more time from a targeted region of the gut.
Natural peristaltic motion gives the pill mobility enabling it to travel through the GI tract without any active parts.
Human trials needed
The University of Guelph team say that the sampling function of the pill has been tested in vitro and in vivo in pigs and primates adding that clinical trials will be needed to see if it can be used in humans for clinical care.
"The design of this device makes it incredibly easy to use, posing little risk to the subject being measured, yet providing so much information," said Giovanni Widmer, study co-author and professor of infectious diseases and global health in Tufts Cummings School of Veterinary Medicine.
"Compared to other non-invasive diagnostic devices, this is like having an electrocardiogram for gut health."
Hojatollah Rezaei Nejad, study lead author and post-doctoral fellow at Tufts said, "We have incredible technology to analyse bacterial populations using DNA sequencing techniques.
“But until now have not had a way to sample bacteria throughout the GI tract in a way that was not invasive.
"By sampling non-invasively, this pill could help us better identify and understand the role of different bacterial species in health and disease."
Source: Advanced Intelligent Systems
Published online: DOI: 10.1002/aisy.201900053
“Ingestible osmotic pill for in-vivo sampling of gut microbiome”
Authors: Nejad et al.
